Simulcast radio communications systems are typically employed to provide wide area one-way or two-way radio communications services. In such a system, a source site typically originates (or forwards from another originating site) a signal to be generally broadcast. This signal is routed from the source site to a plurality of remote sites. Each remote site then simultaneously broadcasts the signal with other remote sites to facilitate reception of the signal by receivers within the area covered by the system.
In this way, a receiver outside the operating range of one remote site may still be within the range of one or more other remote sites, thereby reasonably ensuring that the receiver can receive the signal.
One particularly difficult problem with such simulcast systems involves coordinating the various remote sites to ensure that the signals are in fact substantially simultaneously broadcast by each. A failure to accomplish this will result in instances of unacceptable reception coherence as potentially caused by phase offsets, deviation, distortion and the like.
Another problem arises when more than two signals must be transmitted simultaneously; for example, a voice signal and a data signal. Prior art methods of processing such combined signals in a simulcast environment have not always been adequately conducive to supporting necessary levels of reception coherence.
Finally, even when initially properly adjusted for proper reception coherence, the operating performance of a given simulcast system may vary in response to a number of changing operating and environmental factors. No prior art systems provide for a means of allowing a simulcast system to respond in any convenient or efficacious manner to such circumstances.
A need exists for a simulcast system that provides for the substantially simultaneous broadcast of a signal from a plurality of remote sites, particularly where the signal to be broadcast itself includes at least two signals. A need further exists for a system that can adapt one or more of its operating parameters to continually provide transmissions of acceptable reception coherence even when other operating factors or environmental conditions change.